CARSON, Calif. (AP)  A fire that broke out at a Southern California oil refinery was quickly extinguished Monday with no reported injuries and no disruption in production expected, a plant spokesman said.

The fire at the Tesoro Los Angeles Refinery in Carson was discovered at 10 a.m. in a pipe containing fuel gas.

The Los Angeles County Fire Department was contacted, but fire officials said Tesoro employees already had the blaze out by the time they arrived.

“At this time the fire has been extinguished and the incident is under control and contained,” Tesoro spokesman Brendan Smith said in an email. “There were no injuries reported.”

He said the cause is still unknown and under investigation.

“Refinery production was unaffected by the incident and Tesoro will be able to fulfill contractual product supply commitments,” Smith added.

The company and county agencies tested air quality for the plant and surrounding community but found no danger and gave the area an “all clear” by early afternoon.

The plant, which covers 930 acres near the Port of Long Beach, employs 1,450 people.

It refines heavy crude from California”s San Joaquin Valley and Los Angeles Basin as well as crudes from the Alaska North Slope, South America, West Africa and other international sources.